Field of the Invention
The present invention relates to a pneumatic tire, and in particular, relates to a pneumatic tire used for traveling on muddy roads.
Description of the Related Art
All-season tires for use on dry and muddy roads usually include a tread portion having a block pattern with a plurality of blocks divided between circumferential main grooves and lateral grooves, foe example. Conventionally, in order to improve muddy road performance of such tires, it is proposed increasing volume of lateral grooves for generating large traction on muddy roads by offering large mud shearing force.
The tire having lateral grooves having large groove volume, however, tends to have disadvantage with respect to noise performance on dry roads. For example, pipe resonance noise is often generated in the main grooves during traveling straight ahead on dry roads, and then it tends to easily spread outside the tire from the tread edges through lateral grooves.
Japanese unexamined Patent Application Publication No. 2012-218652 discloses an all-season tire that is expected to have a superior noise performance as well as muddy road performance.
However, such a tire disclosed above has room for improving noise performance on dry roads.